1. Field of the Invention
The invention relates to a process for the treatment of waste sheet floor covering material for the purpose of converting it into raw material to be used in the manufacture of fiber reinforced tile floor material.
2. Description of the Prior Art
U.S. Pat. Nos. 3,056,224 and 3,887,678 disclose a sheet vinyl floor covering material which has an asbestos containing backing material fastened to a vinyl wear layer material.
U.S. Pat. No. 2,773,851 discloses vinyl composition for making a vinyl tile made with filler material.
U.S. Pat. No. 3,836,486 discloses an invention related to the reclamation or recovery of vinyl chloride polymer compositions from scrap plastics.
U.S. Pat. No. 3,027,599 discloses another patent relating to a method of recovering scrap to make a new article.
Finally, U.S. Pat. No. 4,020,020 is Applicant's patent on the recovery of scrap sheet floor through the use of a Banbury mixer. A Banbury mixer is a shear mixer but does not produce the same high degree shear stress that a Henschel mixer will produce. The Banbury mixer masticates the floor covering material under pressure and, after a period of mixing, the raw materials are added to the Banbury mixer and further mixing is carried out. This then results in a mix which can then be further used in another mix to form a floor tile. In the invention herein, a plasticizer is utilized in the initial masticating stage and assists in the separation of the felted fibrous backing from the non-fibrous resin surface. This particular masticating step can not be carried out in a Banbury mixer to give the desired result and must be carried out in a Henschel mixer which generates a high shear stress and moves the mix in a continuous circular path due to centrifugal action. The Henschel mixer is not a mixer that operates under a pressure such as does the Banbury mixer.